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        검색결과 17

        2.
        2020.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The sunspot area is a critical physical quantity for assessing the solar activity level; forecasts of the sunspot area are of great importance for studies of the solar activity and space weather. We developed an innovative hybrid model prediction method by integrating the complementary ensemble empirical mode decomposition (CEEMD) and extreme learning machine (ELM). The time series is first decomposed into intrinsic mode functions (IMFs) with different frequencies by CEEMD; these IMFs can be divided into three groups, a high-frequency group, a low-frequency group, and a trend group. The ELM forecasting models are established to forecast the three groups separately. The final forecast results are obtained by summing up the forecast values of each group. The proposed hybrid model is applied to the smoothed monthly mean sunspot area archived at NASA's Marshall Space Flight Center (MSFC). We find a mean absolute percentage error (MAPE) and a root mean square error (RMSE) of 1.80% and 9.75, respectively, which indicates that: (1) for the CEEMD-ELM model, the predicted sunspot area is in good agreement with the observed one; (2) the proposed model outperforms previous approaches in terms of prediction accuracy and operational efficiency.
        4,000원
        4.
        2020.11 구독 인증기관 무료, 개인회원 유료
        Product labels are one way for advertisers to provide information to purchasers on product quality (Atkinson & Rosenthal, 2014). Label policies have been issued to promote information disclosure on food products in some developed countries. Recent years have also seen increasing attempts to promote healthy eating in emerging markets. In China, nutrition labels became mandatory under the nutrition labeling acts. The laws require nutrition information to be presented at the point of purchase as well as in establishments where food is prepared or consumed. Additionally, similar actions were taken by India (India Ministry of Health and Family Welfare, 2011), Mercosur members and in South Africa (Brazilian Ministry of Health, 2012; Institute of Food Technologists [IFT], 2011).
        3,000원
        5.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Nanoporous carbon/MnO2 (C–MnO2) composites with foam-like structure based on modified nitrile butadiene rubber were achieved by thermal treatment, followed by alkaline solution etching and dipping method. The XRD, nitrogen adsorption and desorption, and SEM and TEM were used to characterize the microstructure of the obtained C–SiO2, C and C–MnO2. Finally, all the obtained samples have been used in three-electrode system to study the electrochemical properties including cyclic voltammetry, galvanostatic charge/discharge and AC impedance for supercapacitor. The study found that the specific capacity of C–MnO2 electrode material for supercapacitor could reach as high as 109 F/g under the current density of 0.5 A/g, which is much higher than those of the other two. These superior electrochemical properties are attributed to the synergistic effect MnO2 particles with the C matrix which functions as a conductive support.
        4,000원
        6.
        2018.07 구독 인증기관 무료, 개인회원 유료
        Product labels are one way for advertisers to provide information to purchasers on product quality (Atkinson & Rosenthal, 2014). Label policies have been issued to promote information disclosure on food products in some developed countries. Recent years have also seen increasing attempts to promote healthy eating in emerging markets. In China, nutrition labels became mandatory under the nutrition labeling acts. The laws require nutrition information to be presented at the point of purchase as well as in establishments where food is prepared or consumed. Additionally, similar actions were taken by India (India Ministry of Health and Family Welfare, 2011), Mercosur members and in South Africa (Brazilian Ministry of Health, 2012; Institute of Food Technologists [IFT], 2011). While nutritional labeling has received a lot of attention both in academia and from the press, some key gaps remain in the nutrition labeling literature. First, a great deal of marketing research has focused on consumer responses (e.g., Balasubramanian & Cole, 2002; Hieke & Taylor, 2012; Ippolito & Mathios, 1995; Parker & Lehmann, 2014; Shah, Bettman, Ubel, Keller, & Edell, 2014) and firm responses (e.g., Moorman 1998; Moorman, Du, & Mela, 2005; Moorman, Ferraro, & Huber, 2012) to nutrition labeling laws. Although stock market investors express greater interest in information about nutrition issues that can be integrated into financial analyses (Global Access to Nutrition Index [ATNI] Investor Statement, 2013), the issue of how standardized information requirements affect investors’ responses in financial markets has been understudied. As used here, standardized product-information disclosure refers to a requirement to present facts about firms’ offerings in a common format using uniform metrics (Moorman et al. 2012). Understanding the extent to which investors consider product information-disclosure polices when they make investment decisions is important because a company’s financial health is not only the ultimate measure for the success or failure of any strategic initiative (Luo & Bhattacharya, 2009), but also one of the most important measures of public policy effectiveness (Joshi & Hanssens, 2010; Srinivasan & Hanssens, 2009; Schwert, 1981). Moreover, urgent concerns have spilled over from the product market to the financial market (Chen, Ganesan, & Liu, 2009) due to the enormous economic costs and damage to firms’ reputations in product-harm crises (e. g., melamine contamination in several Chinese brands of infant milk powder) (Ngo, 2014). Another gap in the literature is how nutritional-labeling requirements affect emerging markets. In contrast to the situation in long-developed countries, emerging markets are subject to different pressures for food marketers and thus a distinctive environment surrounds the regulation of food product labeling. In China, food safety and quality is considered an urgent concern, and the issue has forced regulators and companies to take action (Yan, 2008). Unlike mature stock markets, the majority of investors in China are individuals (Chen, Li, & Shi, 2010). The Chinese markets are under-regulated and deficient in gathering and disseminating information to private or public organizations, and it is difficult for listed firms with insufficient records to form reputations (Singh et al., 2005). As a result, information asymmetry is accentuated and imperfect signals released from firms highly impact investor decisions. Thus, examining the effectiveness of labeling requirements in developing economies is important as is comparing these results to those found in more developed countries. Despite the importance of the issue in emerging markets, empirical work for investigating investor response to the public policy of nutrition labeling (Ghani, & Childs, 1999) or firms’ nutrition claim strategies (Cao & Yan, 2016) has been restricted in developed markets (e.g., the U.S.). Little is understood the changes in corporate financial performance because of regulations requiring product information disclosure in emerging markets. As a result of the pressures for consumer protection and regulation, it is increasingly important for policy makers to be able to understand the financial consequences of such regulation because of information disclosure policies (Moorman et al., 2005). Thus, an additional contribution of this study is to help better inform the policy debate in emerging markets. To fill these research gaps, we investigated the influence of the influx of standardized product information on the stock market. Specifically, we conducted an event study to examine the effect on firms’ stock values from the issuance of the food nutrition label acts (FNLAs) in China, a fast-growing emerging market. The acts require food manufacturers to provide standardized nutritional information on pre-packaged food labels. This study contributes to the marketing literature on the financial impact of regulation in emerging markets. In China, on the day the FNLA was issued, they were associated with positive abnormal stock returns of related firms. This result is contrary to the study by Ghani and Childs (1999) that reported that the NLEA passage showed a negative impact on firms’ stock prices. Second, the financial value from the issuance of regulations was strengthened by three marketing leverages—advertising, donations, and R&D. Finally, although Moorman et al. argued that the NLEA increased the number of small-share firms exiting the U.S. market (Moorman et al., 2005), we found that in the short term, large firms benefited less than small firms from product information disclosure in China’s stock market. These findings provide empirical evidence that regulatory controls create changes in shareholder wealth and provide an assessment of the financial market’s perceptions regarding the role of mandatory product- information disclosure in future corporate growth. In addition, evidence of the effects of regulatory changes on wealth is of significant value to policymakers and market participants as they evaluate the benefits and costs of information disclosure in emerging markets.
        3,000원
        7.
        2018.07 구독 인증기관·개인회원 무료
        The purpose of this study was to investigate the relationship among the service quality, professional competence and loyalty of China tourists visiting Taiwan. A crosssectional survey was used to collect usable data from the China tourists who participate in group tourism to Taiwan. The result indicate that the China tourists felt the service quality of “meal” in Taiwan is the best and good feeling in “professional knowledge” of tour guide. In addition, this study found that the professional competence of tour guide has an intermediary effect between the quality of tourist services and tourist loyalty. The quality of tourism service can positively influence the loyalty of China tourists to Taiwan, meanwhile, the quality of tourism service can positively affect the professional competence of tour guide and the professional competence of tour guide can positively affect the loyalty of China tourists travel to Taiwan. According to the results, the study found that travel agencies should focus on the training of tour guide, which help travel agencies to raise the value of travels product and attract more tourist.
        8.
        2018.07 구독 인증기관 무료, 개인회원 유료
        Introduction In order to solve the information asymmetry and make full use of resources (unused goods, spare capacity and so on), the sharing economy, which based on the application of mobile internet technology and focused on the consumption of the right to use, is developing rapidly. Lack of trust is considered to be one of the important problems hindering the development of sharing economy. Möhlmann (2015) said that trust is a fundamental determinant of sharing economy development and ensuring shared satisfaction. At present, sharing economy enterprises have established product evaluation system and docked a third party credit rating system (i.e. Zhima Credit) to promote consumers’ trust. However, with most enterprises are becoming more and more consistent in evaluation and credit rating system, there is a new problem emerged: how to further deepen consumers’ trust in order to promote consumers’ intention to participate continuously (Zucker, 1986; Lewis & Weigert, 1985). Granovetter (1985) mentioned that trust is the product of social relationships. Botsman and Rogers (2011) made it clear that social networks play an important role in building trust in sharing economy. And people are always more willing to accept the opinions of people who have social relations with them (Lu, Zhao, & Wang, 2010). Hence, with the feature of participant of everyone in sharing economy, it is necessary to further strengthen consumers’ trust through the social interaction among consumers and between consumers and sharing platforms. Theoretical Development Sharing economy is based on LBS and other new technologies to realize the matching of supply and demand information across time and space. And to a certain extent, it solves the problem of information asymmetry in the era of e-commerce. Yet consumer have new requirements for product information. For example, consumers are more concerned about whether the utility of products and services can meet their needs (i.e. some consumers are more concerned about when to reach their destination than the performance of the car). But it is difficult for company to understand each everyone of consumers’ utility preference and publish product utility information based on these preferences (Xie & Gerstner, 2007). Because this kind of utility preference has the characteristic of timeliness and personalization. Therefore, consumers’ perceived uncertainty about the utility of the product will also affect the consumers’ trust. In summary, we then address these research questions:(1) can the promotion of trust between consumers and sharing platforms be achieved through the socializing of sharing platforms and then affect consumers’ intention to participate continuously; (2) if so, which type of privacy protection method and social information can promote consumer trust; and (3) does the impact of sharing platform socialization on consumer trust vary according to consumers’ concerns about the perceived utility uncertainty of the product. Research Design We then address these issues using experiment data. The first experiment was a 2 (social media: have, not have) x 2 (individual trust propensity: trust, not trust) between-subject design on the intention to trust sharing platform and participant continuously. Perceived utility uncertainty was added to this design as a moderator. Moreover, the second experiment was a 2 (social information type: hedonic, utilitarian) x 2 (degree of privacy protection: week, strong) between-subject design on the intention to trust sharing platform. Our scales come from existing scales and optimize it according to the characteristics of sharing economy (Schneider, 1999; Dhar & Wertenbroch, 2000; McKnight, Choudhury, & Kacmar, 2002). Results and Conclusion The results of the first experiment show that whether or not the social platform has no significant impact on the consumer trust if the individual tends to trust others. And for individuals who tends to do not trust others, they are more likely to trust socialized sharing platforms. The higher the consumer perceived utility uncertainty is, the higher (lower) trust of the consumer platform in the socialized (not socialized) sharing platform. For the second experiment results, in the context of sharing economy, the utilitarian information has a greater positive impact on the consumer trust than the hedonic information. In addition, the stronger the privacy protection of sharing platforms, the higher the trust of consumes. This study makes several academic contributions. First, we extend the topic of socialization to sharing economy context. Second, we add the perceived utility uncertainty as a moderator, and supplement the role of perceived uncertainty. This research also provides several practical implications. First, sharing platform can promote their consumers’ trust by establishing their own social platform. This platform can be used as a differentiated competitive strategy for sharing platform. Second, sharing platform should guide consumers to share utilitarian information (i.e. weather for specific place or real time traffic) to improve consumer satisfaction. Third, sharing platform can access consumer preference information through this social platform for further product development and classification.
        3,000원
        9.
        2018.07 구독 인증기관 무료, 개인회원 유료
        Introduction In order to solve the information asymmetry and make full use of resources (unused goods, spare capacity and so on), the sharing economy, which based on the application of mobile internet technology and focused on the consumption of the right to use, is developing rapidly. Lack of trust is considered to be one of the important problems hindering the development of sharing economy. Möhlmann (2015) said that trust is a fundamental determinant of sharing economy development and ensuring shared satisfaction. At present, sharing economy enterprises have established product evaluation system and docked a third party credit rating system (i.e. Zhima Credit) to promote consumers’ trust. However, with most enterprises are becoming more and more consistent in evaluation and credit rating system, there is a new problem emerged: how to further deepen consumers’ trust in order to promote consumers’ intention to participate continuously (Zucker, 1986; Lewis & Weigert, 1985). Granovetter (1985) mentioned that trust is the product of social relationships. Botsman and Rogers (2011) made it clear that social networks play an important role in building trust in sharing economy. And people are always more willing to accept the opinions of people who have social relations with them (Lu, Zhao, & Wang, 2010). Hence, with the feature of participant of everyone in sharing economy, it is necessary to further strengthen consumers’ trust through the social interaction among consumers and between consumers and sharing platforms. Theoretical Development Sharing economy is based on LBS and other new technologies to realize the matching of supply and demand information across time and space. And to a certain extent, it solves the problem of information asymmetry in the era of e-commerce. Yet consumer have new requirements for product information. For example, consumers are more concerned about whether the utility of products and services can meet their needs (i.e. some consumers are more concerned about when to reach their destination than the performance of the car). But it is difficult for company to understand each everyone of consumers’ utility preference and publish product utility information based on these preferences (Xie & Gerstner, 2007). Because this kind of utility preference has the characteristic of timeliness and personalization. Therefore, consumers’ perceived uncertainty about the utility of the product will also affect the consumers’ trust. In summary, we then address these research questions:(1) can the promotion of trust between consumers and sharing platforms be achieved through the socializing of sharing platforms and then affect consumers’ intention to participate continuously; (2) if so, which type of privacy protection method and social information can promote consumer trust; and (3) does the impact of sharing platform socialization on consumer trust vary according to consumers’ concerns about the perceived utility uncertainty of the product. Research Design We then address these issues using experiment data. The first experiment was a 2 (social media: have, not have) x 2 (individual trust propensity: trust, not trust) between-subject design on the intention to trust sharing platform and participant continuously. Perceived utility uncertainty was added to this design as a moderator. Moreover, the second experiment was a 2 (social information type: hedonic, utilitarian) x 2 (degree of privacy protection: week, strong) between-subject design on the intention to trust sharing platform. Our scales come from existing scales and optimize it according to the characteristics of sharing economy (Schneider, 1999; Dhar & Wertenbroch, 2000; McKnight, Choudhury, & Kacmar, 2002). Results and Conclusion The results of the first experiment show that whether or not the social platform has no significant impact on the consumer trust if the individual tends to trust others. And for individuals who tends to do not trust others, they are more likely to trust socialized sharing platforms. The higher the consumer perceived utility uncertainty is, the higher (lower) trust of the consumer platform in the socialized (not socialized) sharing platform. For the second experiment results, in the context of sharing economy, the utilitarian information has a greater positive impact on the consumer trust than the hedonic information. In addition, the stronger the privacy protection of sharing platforms, the higher the trust of consumes. This study makes several academic contributions. First, we extend the topic of socialization to sharing economy context. Second, we add the perceived utility uncertainty as a moderator, and supplement the role of perceived uncertainty. This research also provides several practical implications. First, sharing platform can promote their consumers’ trust by establishing their own social platform. This platform can be used as a differentiated competitive strategy for sharing platform. Second, sharing platform should guide consumers to share utilitarian information (i.e. weather for specific place or real time traffic) to improve consumer satisfaction. Third, sharing platform can access consumer preference information through this social platform for further product development and classification.
        3,000원
        10.
        2018.07 구독 인증기관 무료, 개인회원 유료
        Introduction Online shopping has become an important part of people’s daily lives. The very nature of online shopping makes it unlikely for consumers to examine products with their senses (e.g., touch, smell) as they can do in offline stores. The consumer obtains information from a variety of online sources (sellers, other buyers, and third parties) to assess a product and make a purchase decision. This variety of online information (e.g., product description, reviews and ratings) informs and persuades consumers. While sellers’ decisions comprise most information displayed on their product’s website, other information is shown because consumers have a moral, ethical, and legal “right” to know (e.g., ingredients, weight, size) (Jacoby, Speller, & Berning, 1974). Regarding the latter information, some countries (e.g., the U.S., China, Canada, the EU and India) have regulations that require pre-packaged food manufacturers to provide a nutrition-fact label and claims displaying standardized information on product packaging (Health Canada, 2010). We ask the following question to public policy makers and marketers: Should online pre-packaged food shops also need to present nutrition facts? There are two perspectives one might adopt regarding the array of information confronting online shoppers. The first perspective deals with human information processing. This position maintains that humans’ ability to assimilate and process information has finite limits during any given unit of time, and that once these limits are surpassed, behavior tends to become confused and dysfunctional (Miller, 1956; Driver & Streufert, 1969). Conceivably, such information overload might also occur in online shopping. Online shoppers often make their selections from a range of products, each with an array of information. Moreover, they make such purchase decisions within a relatively short time period. An alternative perspective is that nutrition-fact information provides key cues for consumers to assess product quality in the online marketplace. Cues can be categorized as extrinsic or intrinsic to the product (Maheswaran & Chaiken, 1991; Anderson, 1981). Extrinsic cues are product-related attributes that can be altered whereas intrinsic cues are inherent to the product itself (e.g., ingredients) and cannot be easily altered (Rao & Monroe, 1988; Purohit & Srivastava, 2001). An online shopper's evaluation of a product is based upon both intrinsic and extrinsic cues. In the online shopping environment, few intrinsic cues are available to consumers and the disclosure of nutrition facts (an intrinsic product feature) can help to fill this gap. Theoretical Development The understanding of how nutrition information presentation influences online food sales is a substantial topic for both industry and academia. With the convenience of online shopping, the potential for food producers and retail stores to take their products online is enormous. eMarketer (2014) reports that online food and beverage purchases increased 15.2% in U.S. retail ecommerce sales, and that this trend will remain consistent. Online food shopping is extremely popular in China, with 92% of consumers purchasing food or beverages at least once a month (Weber Shandwick, 2014). Moreover, eMarketer (2016) reports that by 2020, one-fourth of China's online purchases will be made directly from foreign websites or from third-party platforms. Thus, it is important for other countries to learn about the Chinese market. Among these potential issues, whether nutrition-fact information affects consumer purchase decisions in the online shopping context remains unexplored. Nutrition-fact labels have proven to be useful cues for consumer purchasing decision in offline conditions (Shah, Bettman, Ubel, Keller, & Edell, 2014). However, researchers have been unable to determine the effects of nutrition information in online conditions with network virtualization (Mavlanova, Benbunan-Fich, & Koufaris, 2012) and information multiplicity. In addition, the nutrition information disclosed by online sellers may cue consumers to acquire healthy food. Previous research has found that when information pertaining to a food’s nutritional content is provided, less-healthy food tastes better (Raghunathan, Naylor, & Hoyer, 2006). This literature raises the issue of whether nutrition information is more effective for healthy or unhealthy products. In summary, we investigate the effect of nutrition-fact information on online food shopping. The research questions address: (1) whether and how nutrition-fact information influences food sales in online conditions; (2) how nutrition-fact information interacts with other online extrinsic cues (i.e., word of mouth and historical sales); and (3) whether nutrition-fact information is more effective for healthy or unhealthy products. Research Design We then address these issues using panel data collected from Taobao.com (the largest online shopping platform in China). We selected 45 days as our study period, and the sample comprised 273 sellers. In addition, we conduct an experiment using an eye-tracking system to test the necessity and helpfulness of nutrition-fact information. Results and Conclusion The results show that the nutrition-fact information has a significant impact on sales. More specifically, consumers are more likely to choose sellers with the nutrition-fact information, and the healthy (unhealthy) food with nutrition-fact information tends to attract more (fewer) purchase. In addition, our results reveal some interesting interactions between nutrition-fact information and other cues. Specifically, WOM and historical sales strengthen the sales impact of nutrition-fact information. Our eye-tracking experiment leads to several interesting results. First, consumers pay attention to nutrition-fact information and spend considerable time reading it. Second, a long fixation length on nutrition-fact information would reasonably increase sales. This study makes several academic contributions. First, we extend the topic of nutrition information to an e-commerce context. Second, this is one of the first studies to examine the role of nutrition-fact information from an experimental perspective. Third, we supplement the findings of previous studies on the role of food type. This study also provides several practical implications. First, governments could require online sellers to reveal nutrition information in a truthful and detailed manner at the point of sale. In addition, labeling policies not only increase nutrition awareness and protect consumers, but they can also offer a profitable path for marketers. Second, sellers should design nutrition information and other cues strategies jointly. Third, compared with unhealthy food, nutrition-fact information is more effective for the purchase of healthy food. Sellers might be encouraged by this trend and consider more strategies to display nutrition-fact information on healthy food.
        3,000원
        11.
        2016.07 구독 인증기관·개인회원 무료
        Recent decades have seen a number of policies have been launched to promote information disclosure on food products marketed in developed countries. There has also been increasing efforts to promote healthy eating in developing economies (Cowburn & Stockley 2005). A good example appears in China, where, in an effort to improve health education, nutrition labels became mandatory under the Nutrition Labeling Act (NLA) since 2013. Additionally, food labeling regulations were issued by India, Mercosur members and South Africa. While nutritional labeling has received a lot of attention both in academia and from the press, there are some key gaps in the nutrition labeling literature. One issue of how standardized information requirements affect firm marketing responses (e.g., advertising levels. R&D investment, and corporate social responsibility programs) and performance has been understudied. Another clear gap in the literature is how nutritional labeling requirements affect developing economies.
        12.
        2015.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        We first deduce a uniform formula forthe Fermi energy of degenerate and relativistic electrons in the weak-magnetic field approximation. Then we obtain an expression of the special solution for the electron Fermi energy through this formula, and express the electron Fermi energy as a function of electron fraction and matter density. Our method is universally suitable for relativistic electron- matter regions in neutron stars in the weak-magnetic field approximation.
        3,000원
        14.
        2014.07 구독 인증기관·개인회원 무료
        This study employs a trading dataset from a top investment bank in Taiwan to examine whether and how mutual fund advertising influences fund consumers’ redemption behavior, and whether the effect of advertising differs between small- and large-amount fund consumers. The evidence of this study shows that, on average, fund consumers redeem more non-advertised funds as their returns increase, while fund advertising slows their redemptions. The results from quantile regression show that fund advertising plays an important role in affecting redemption-performance sensitivity of large-amount and medium-amount investors. After taking advertising into account, large-amount and medium-amount investors reduce their fund redemptions. The results suggest that advertising, as a transmission of information, varies with investors’ wealth levels and that these differences in advertising matter to investors’ redemptions. This study contributes to understanding the role of advertising in fund consumers’ realized behavior and is useful for fund companies because they can more efficiently allocate limited resources such as advertising to support the growth of fund assets under management.
        15.
        2014.07 구독 인증기관 무료, 개인회원 유료
        Customers are regarded as the key intangible assets of a company. It is necessary to have the capability to anticipate customer value. The study discusses the relationship among customer value anticipation, product innovativeness, and customer lifetime value from customer perspective. 178 MBA students were surveyed by questionnaire in this study. The results show that customer perceived customer value anticipation can significantly influence product innovativeness. Product innovativeness not only positively affects customer lifetime value, but also plays a partial mediating role between customer value anticipation and customer lifetime value. Both functional and emotional advertising can play a moderating role on the relationship between product innovativeness and customer lifetime value. At the end, managerial implications are discussed.
        4,300원
        16.
        2015.07 서비스 종료(열람 제한)
        Although the overall structure of the chloroplast genome is generally conserved, a number of sequence variations have been identified, which are valuable for plant population and evolutionary studies. Here, we constructed a chloroplast variation map of 30 landrace rice strains of Korean origin, using the Oryza rufipogon chloroplast genome (Genbank: NC_017835) as a reference. Differential distribution of single nucleotide polymorphisms (SNPs) and indels across the rice chloroplast genome is suggestive of a region-specific variation. Population structure clustering revealed the existence of two clear subgroups (indica and japonica) and an admixture group (aus). Phylogenetic analysis of the 30 landrace rice strains and six rice chloroplast references suggested and supported independent evolution of O. sativa indica and japonica. Interestingly, two “aus” type accessions, which were thought to be indica type, shared a closer relationship with the japonica type. One hypothesis is that “Korean aus” was intentionally introduced and may have obtained japonica chloroplasts during cultivation. We also calculated the nucleotide diversity of 30 accessions and compared to six rice chloroplast references, which shown a higher diversity in the indica and aus groups than in the japonica group in lower level substitution diversity.
        17.
        2015.07 서비스 종료(열람 제한)
        Rice germplasm collections continue to grow in number and size around the world. Since maintaining and screening such massive resources remain as a great challenge, it is important to establish piratical ways to manage them. A core collection, by definition, refers to a subset of entire population but preserves most of the possible genetic diversity, enhancing the efficiency for germplasm utilizations. Here we reports the whole genome resequencing of the 137 Korean rice core set (KRICE_CORE) that represents 25,604 rice germplasms deposited in Korean genebank of Rural Development Administration (RDA). We implemented the Illumna HiSeq 2000 and 2500 platform to produce short reads and then assembled those with 9.8x depth using Nipponbare as a reference. Comparisons of the sequences with the reference genome yield more than 15 million(M) single nucleotide polymorphisms (SNPs) and 1.3M insertion/deletion (INDELs). Phylogenetic and population analyses using 2,046,529 high quality SNPs successfully assigned each rice accessions to the relevant subgroups, suggesting those SNPs comprehensively capture evolutionary signatures accumulated in rice subpopulations. Furthermore, genome-wide association studies (GWAS) for 4 exemplary agronomic traits from the KRIC_CORE manifest the utility of KRICE_CORE, identifying previously defined gene or novel genetic polymorphisms that potentially regulate the important phenotypes. This study provides strong evidences that the size of KRICE_CORE is small but contains such a high genetic and functional diversity across the genome. Thus those resequencing results will be useful for future breeding, functional and evolutionary studies in the post-genomic era.